I am running Ubuntu and am using an Atheros chipset WiFi card to run some ad-hoc tests. I am running an iperf throughput test, digitizing the RF, attenuating the signal, going back to RF, and looking at the RSSI on a receiver laptop. I noticed that attenuation levels are not consistently the same value if I don't walk myself to them the same way. I think this is due to hysteresis and thresholds in the WiFi cards, but I am not sure how to get around that.
Is there a way to tweak the thresholds, or clear out the hysteresis between tests so that the cards are starting "fresh" each time?